Pressurized fluid dispensers, such as aerosol spray cans, are known wherein a container is filled with a fluid, or mixture of fluids, and with a quantity of pressurized propellant gas. Typically, a rigid or semi-rigid dip tube is positioned within the container to receive fluid from the bottom of the container and to transfer the fluid to an externally-actuatable valve assembly in response to actuation of the valve. In the use of such dispensers, it is necessary to hold the container in an upright orientation in order to maintain the collection end of the dip tube positioned within the fluid to be dispensed. When the dispenser is inverted, the supply of fluid moves to the valve end of the can, and the inlet end of the dip tube then extends into the volume occupied by the propellant gas. Actuation of the valve then results in loss of propellant without dispensing the desired fluid. It would be desirable to provide a pressurized fluid dispenser that is configured to dispense a desired fluid in both an upright and inverted orientation.
Known devices for providing an invertible pressurized fluid dispenser include a gravity-actuated valve mechanism for selectively withdrawing fluid from two alternative fluid collection inlets positioned within the container. Such a selective valve mechanism can be incorporated into a dip tube assembly, as exemplified in U.S. Pat. No. 2,315,263 or in U.S. Pat. No. 3,545,488. Alternatively, such a mechanism can be constructed as part of the dispensing valve as exemplified in U.S. Pat. No. 5,222,636. Such a gravity-actuated valve mechanism requires precision-machined internal moving parts and seating surfaces in order to provide a gas-tight seal against the pressure exerted by the propellant gas through the inlet opening which is to be sealed in either orientation of the dispenser. Such a gas-tight seal would be difficult to obtain in dispensers employed for dispensing fluids of various viscosities or fluids containing suspended particulate materials.
Another approach to providing an invertible pressurized fluid dispenser employs a flexible dip tube having a weighted inlet end which is freely suspended within the container in order to move with the contained fluid under the influence of gravity. Such assemblies are exemplified in U.S. Pat. Nos. 3,088,680, 3,490,656 and 3,580,430. Such devices are limited in application to containers that are suitably short to avoid kinking, twisting, knotting, or other random deformation of the flexible dip tube which may obstruct or reduce fluid flow. It would be desirable to provide an internal fluid collection apparatus wherein an inlet end of the apparatus may be translated to the fluid-containing part of the container, and in which the fluid transmission means maintains a predetermined configuration to avoid random deformation.